Diagnostic Testing and Rehabilitation of Well W10

Regional Municipality of Waterloo
Franklyn Smith, C.E.T., Water Infrastructure Specialist Regional Municipality of Waterloo 519-575-4749
Well Rehabilitation and Lineshaft Pump Service


This project consisted of diagnostic testing and rehabilitation of Well W10 in order to improve efficiency and overall production of the well.  A step drawdown test was performed to determine baseline well and pump performance conditions, and results were compared with history performance data to determine the level of plugging.  A pre rehabilitation video inspection (Photo 1) and flow profile was conducted to determine the condition of the well screen and casing as well as the distribution of the flow across the screened intervals.  This information was used to develop and implement a rehabilitation program specific to the conditions present.  
The well was rehabilitated using a combination of acid, air displacement surging, airlifting and treatment with the Ener-Jet system.  Post rehabilitation testing and video inspection showed that these efforts were successful in restoring the performance and condition of the well to as-constructed levels (Photo 2).
Concurrent with the testing and rehabilitation program, pump performance was also evaluated and compared with the manufacturer’s stated performance.  Considering that the pump was installed new in 2005 and was operating as per manufacturer’s specifications, the pump was not completely disassembled and inspected. The column pipe was recoated with NSF coating and the column end faces were cleaned in preparation for reinstallation. 
Lotowater’s thorough review of the well’s history revealed that the well had a history of sand production.  Therefore, Lotowater took necessary steps to install a Rossum sand tester to quantify the sand production and ensure that the current concentrations met AWWA and other industry standards for municipal use.
As with all Lotowater projects, a detailed report including analysis of rehabilitation results, comparison of well performance data to historical data, as-constructed drawing, pump installation test record, flow profile, as well as DVDs of the video inspections were provided to the client.  All reports were submitted in PDF and hard copy format.